Who told the first lie in the Bible?
God
God said to Adam, "But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die."
But Adam ate from that tree (Gen 3:6) and yet didn't die that day, but rather lived to be 930 years old (Gen 5:5). This is the first lie in the Bible - and it was made by God.
Genesis 2:17
